Up to now, more than 700 encoding systems have been disclosed for inputting Chinese characters. However, in these systems, Chinese characters are not encoded directly using English alphabet. Thus it is still inconvenient to input and outpout Chinese characters into and from computers like alphabetic languages and to use Chinese characters in communication facilities and automatic printing systems.
Among the prior art methods, five-stroke encoding system invented by Wang Yong Min is suitable to standard keyboard, with only a few duplicate codes. However, the operators have to master 125 radicals and 25 pithy formulas defined by the inventor. And this makes non-typists shrink back at the sight of the great amount of what have to be memorized. This defect is due to the fact that the method is soly based on character forms.
With the "full-information" code invented by Du Bing Chan, an operator also has to remember 100 radicals in common use and 8 first pronounceable letters of 8 strokes. It is difficult to solve the problem of alphabetizing Chinese characters by just concerning the similar pronunciation between Chinese characters and alphabetic language, regardless of character forms. Owing to many dialects and slangs, the above method is hard to be popularized.
Although Chen Ai Wen, the inventor of "Biao Xing" (indicating form) code, discovered that there obviously exist a few letters of English alphabet in Chinese characters, he did not find this objective law: all Chinese characters are formed by letters of English alphabet piled up like toy bricks. Thus, he adopted the method for inputting Chinese characters by means of the mixture of four kinds of information associated with phonetic alphabet, numerals, component radicals and stroke blocks similar to letters, and a few letters of English alphabet to input Chinese characters in conventional way. Thus users have to memorize a lot of rules.